A research study published in Lancet in 1998 suggesting a link between one popular vaccine combination, the Mumps-Measles-Rubella or MMR vaccine, only sampled 12 patients. The Diphtheria, tuberculosis and pertussis, or DtaP vaccine, seems to have found itself guilty by association.

But that hasn't stopped true believers -- like Hollywood couple Jim Carrey and Jenny McCarthy, who naturally have many years of medical training and advanced degrees in immunology -- from endangering their children and those of other parents by withholding or delaying immunization.

Jackson West personally believes that socialization, along with vaccination, is your best defense.